fitzhardinge | 59cfddc | 2004-03-17 18:20:46 +0000 | [diff] [blame] | 1 | /* JSGF: no idea what this is actually doing, but it really gives the |
| 2 | signals/sigaltstack/threads machinery a working out */ |
| 3 | /** |
| 4 | * Compile with: |
| 5 | * gcc -g -Wall -lpthread -o susphello susphello.c |
| 6 | * |
| 7 | * Author Magnus Ihse, ihse at bea.com |
| 8 | */ |
| 9 | |
| 10 | #include <signal.h> |
| 11 | |
| 12 | |
| 13 | #include <errno.h> |
| 14 | #include <stddef.h> |
| 15 | #include <pthread.h> |
| 16 | #include <signal.h> |
| 17 | #include <stdlib.h> |
| 18 | #include <string.h> |
| 19 | #include <sys/resource.h> |
| 20 | #include <unistd.h> |
| 21 | #include <sys/syscall.h> |
| 22 | #include <dlfcn.h> |
| 23 | |
| 24 | |
| 25 | #include <pthread.h> |
| 26 | #include <unistd.h> |
| 27 | #include <string.h> |
| 28 | #include <netdb.h> |
| 29 | #include <stdio.h> |
| 30 | #include <stdlib.h> |
| 31 | |
| 32 | #define THREAD_COUNT 10 |
| 33 | #define ITER_COUNT 200 |
| 34 | |
| 35 | static volatile int finishedArray[THREAD_COUNT]; |
| 36 | static int pKey; |
| 37 | |
| 38 | static sigset_t srSigset; |
| 39 | |
| 40 | pthread_t main_thread; |
| 41 | |
| 42 | int srSignal = SIGUSR1; |
| 43 | |
| 44 | |
| 45 | void |
| 46 | ptiSrSigHandler(int sig, siginfo_t *sip, void *arg) |
| 47 | { |
| 48 | //ucontext_t *ucontext = (ucontext_t *)arg; |
| 49 | |
| 50 | int mypos = (int) pthread_getspecific(pKey); |
| 51 | |
| 52 | |
| 53 | // int threadPos = (int)pthread_getspecific(srThreadKey); |
| 54 | |
| 55 | // thread->os_context = (OSContextP)&(ucontext->uc_mcontext); |
| 56 | |
| 57 | // Notify suspender that we have been suspended |
| 58 | if (pthread_kill(main_thread, srSignal) == -1) { |
| 59 | perror("pthread_kill"); |
| 60 | exit(1); |
| 61 | } |
| 62 | |
| 63 | finishedArray[mypos]++; |
| 64 | |
| 65 | // printf("this is thread %d: i'm now suspended!\n", mypos); |
| 66 | |
| 67 | // Wait until we are resumed |
| 68 | while (sigwaitinfo(&srSigset, NULL) == -1) { |
| 69 | // Interrupted by SIGSTOP in gdb |
| 70 | if(errno != EINTR) { |
| 71 | perror("sigwaitinfo"); |
| 72 | exit(1); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | // printf("this is thread %d: i'm now resumed!\n", mypos); |
| 77 | |
| 78 | //thread->os_context = NULL; // just for the sake of it... |
| 79 | |
| 80 | // Notify resumer that we have been resumed |
| 81 | if (pthread_kill(main_thread, srSignal) == -1) { |
| 82 | perror("pthread_kill"); |
| 83 | exit(1); |
| 84 | } |
| 85 | // printf("this is thread %d: and I've told Master!!\n", mypos); |
| 86 | |
| 87 | } |
| 88 | |
| 89 | |
| 90 | void |
| 91 | suspendOrResume(pthread_t thread, int i) |
| 92 | { |
| 93 | sigset_t oss; |
| 94 | |
| 95 | // Mask out suspend/resume signal until we explicitly wait for it |
| 96 | sigprocmask(SIG_BLOCK, &srSigset, &oss); |
| 97 | |
| 98 | // Send signal to suspend or resume the thread |
| 99 | if (pthread_kill(thread, srSignal) == -1) { |
| 100 | perror("pthread_kill"); |
| 101 | exit(1); |
| 102 | } |
| 103 | |
| 104 | // printf("sent signal to %d...", i); |
| 105 | // Wait for notification from thread being suspended/resumed |
| 106 | while (sigwaitinfo(&srSigset, NULL) == -1) { |
| 107 | // Interrupted by SIGSTOP in gdb |
| 108 | if(errno != EINTR) { |
| 109 | perror("sigwaitinfo"); |
| 110 | exit(1); |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | // Restore original signal mask |
| 115 | sigprocmask(SIG_SETMASK, &oss, NULL); |
| 116 | |
| 117 | // printf("... okay, %d suspended\n", i); |
| 118 | } |
| 119 | |
| 120 | |
| 121 | |
| 122 | void |
| 123 | initSignalling(void) |
| 124 | { |
| 125 | struct sigaction sa; |
| 126 | |
| 127 | // Signal mask for suspend/resume |
| 128 | sigemptyset(&srSigset); |
| 129 | sigaddset(&srSigset, srSignal); |
| 130 | |
| 131 | // Set up signal handler for suspend/resume |
| 132 | sa.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK; |
| 133 | sa.sa_sigaction = ptiSrSigHandler; |
| 134 | sigfillset(&sa.sa_mask); |
| 135 | sigdelset(&sa.sa_mask, (__SIGRTMIN+1)); |
| 136 | if (sigaction(srSignal, &sa, 0) == -1) { |
| 137 | perror("sigaction"); |
| 138 | exit(1); |
| 139 | } |
| 140 | |
| 141 | // Unblock suspend signal |
| 142 | sigprocmask(SIG_UNBLOCK, &srSigset, 0); |
| 143 | |
| 144 | main_thread = pthread_self(); |
| 145 | } |
| 146 | |
| 147 | |
| 148 | void* setup_altstack(void) { |
| 149 | stack_t ss; |
| 150 | |
| 151 | ss.ss_sp = malloc(20*1024); |
| 152 | if (ss.ss_sp == 0) { |
| 153 | return NULL; |
| 154 | } |
| 155 | ss.ss_size = 20*1024; |
| 156 | ss.ss_flags = 0; |
| 157 | |
| 158 | if (sigaltstack(&ss, NULL) == -1) { |
| 159 | perror("sigaltstack"); |
| 160 | return NULL; |
| 161 | } |
| 162 | return ss.ss_sp; |
| 163 | } |
| 164 | |
| 165 | void takedown_altstack(void* stack) { |
| 166 | struct sigaltstack ss; |
| 167 | int result; |
| 168 | |
| 169 | ss.ss_flags = SS_DISABLE; |
| 170 | ss.ss_sp = (void*)47; // This value should be ignored when ss_flags is SS_DISABLE |
| 171 | ss.ss_size = 29; // This value should be ignored when ss_flags is SS_DISABLE |
| 172 | |
| 173 | { |
| 174 | result = sigaltstack(&ss, NULL); |
| 175 | free(stack); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | void *threadfunc(void *arg) { |
| 180 | int mypos = (int)arg; |
| 181 | int i; |
| 182 | long square = 1; |
| 183 | void* altstack = setup_altstack(); |
| 184 | |
| 185 | pthread_setspecific(pKey, arg); |
| 186 | for (i=0; i < 1000; i++) { |
| 187 | square = i*i + square*mypos; |
| 188 | } |
| 189 | |
| 190 | // wait for signal |
| 191 | while (finishedArray[mypos] == 0) { |
| 192 | struct timespec req, rem; |
| 193 | |
| 194 | req.tv_sec = 0; |
| 195 | req.tv_nsec = 5 * 1000 * 1000; |
| 196 | |
| 197 | nanosleep(&req, &rem); |
| 198 | |
| 199 | }; |
| 200 | |
| 201 | finishedArray[mypos]++; |
| 202 | |
| 203 | takedown_altstack(altstack); |
| 204 | |
| 205 | return NULL; |
| 206 | } |
| 207 | |
| 208 | |
| 209 | int main(int argc, char ** argv) { |
| 210 | pthread_t threads[THREAD_COUNT]; |
| 211 | pthread_attr_t attr; |
| 212 | int result; |
| 213 | int i; |
| 214 | int iteration; |
| 215 | int finished; |
| 216 | |
| 217 | initSignalling(); |
| 218 | |
| 219 | pthread_attr_init(&attr); |
| 220 | pthread_attr_setstacksize(&attr, 128*1024); |
| 221 | |
| 222 | pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); |
| 223 | |
| 224 | pthread_key_create(&pKey, NULL); |
| 225 | |
| 226 | for (iteration = 0; iteration < ITER_COUNT; iteration++) { |
| 227 | #if 0 |
| 228 | if ((iteration % 100) == 0) { |
| 229 | printf("\nStarting run series %i: ", iteration); |
| 230 | } |
| 231 | |
| 232 | if ((iteration % 10) == 0) { |
| 233 | printf("."); |
| 234 | fflush(stdout); |
| 235 | } |
| 236 | #endif |
| 237 | |
| 238 | // Clear array |
| 239 | for (i = 0; i< THREAD_COUNT; i++) { |
| 240 | finishedArray[i] = 0; |
| 241 | } |
| 242 | |
| 243 | // Start threads |
| 244 | for (i = 0; i< THREAD_COUNT; i++) { |
| 245 | result = pthread_create(&threads[i], &attr, threadfunc, (void*)i); |
| 246 | if (result != 0) { |
| 247 | perror("pthread_create"); |
| 248 | exit(1); |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | // printf("all threads started\n"); |
| 253 | // suspend threads |
| 254 | for (i = 0; i< THREAD_COUNT; i++) { |
| 255 | suspendOrResume(threads[i], i); |
| 256 | } |
| 257 | |
| 258 | // printf("now all threads are suspended\n"); |
| 259 | |
| 260 | // resume threads |
| 261 | for (i = 0; i< THREAD_COUNT; i++) { |
| 262 | suspendOrResume(threads[i], i); |
| 263 | } |
| 264 | |
| 265 | |
| 266 | // Join threads |
| 267 | /* |
| 268 | printf("about to join..."); |
| 269 | for (i = 0; i< THREAD_COUNT; i++) { |
| 270 | result = pthread_join(threads[i], NULL); |
| 271 | if (result != 0) { |
| 272 | perror("pthread_join"); |
| 273 | exit(1); |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | printf("...joined"); |
| 278 | */ |
| 279 | // printf("Spin waiting for results\n"); |
| 280 | finished = 1; |
| 281 | do { |
| 282 | struct timespec req, rem; |
| 283 | |
| 284 | req.tv_sec = 0; |
| 285 | req.tv_nsec = 5 * 1000 * 1000; |
| 286 | finished = 1; |
| 287 | |
| 288 | nanosleep(&req, &rem); |
| 289 | |
| 290 | // sleep(1); |
| 291 | for (i = 0; i< THREAD_COUNT; i++) { |
| 292 | if (finishedArray[i] < 2) { |
| 293 | finished = 0; |
| 294 | // printf("no result at: %d, value: %d\n", i, finishedArray[i]); |
| 295 | break; |
| 296 | } |
| 297 | } |
| 298 | // sleep(1); |
| 299 | } while (!finished); |
| 300 | |
| 301 | } |
| 302 | |
| 303 | printf("PASSED\n"); |
| 304 | return 0; |
| 305 | } |